The chelating reaction between glutathione peptides and divalent cadmium ion was used as a typical model for investigating the coordination chemistry of SH-containing peptides and heavy metal ions, which was essential to understand the mechanism of intracellular cadmium detoxification.Here, the mutant (CM113R)7 αHL protein nanopore equipped with a first synthesized per-6-quaternary ammonium-β-cyclodextrin (p-QABCD) was used as nanoreactor and detector to investigate the single-molecule reaction of GSH molecules and Cd2+ ions.Different reaction pathways, intermediates, and products could be recognized.Cd2+-GSH reaction was highly dependent on the solution pH.The Cd(GSH)2 was formed at pH 7.4, while the Cd(GSH)2 and Cd2(GSH)2 were formed at pH 9.0.Cd2(GSH)2 was formed by two possible pathways: (1) A Cd2+ ion primarily coordinated with the thiol group of two GSH molecules to form Cd(GSH)2, and then the second Cd2+ ion quickly incorporated with the deprotonated amino group of Cd(GSH)2 to form Cd2(GSH)2;(2) Two Cd2+ ions separately coordinated with the thiol and deprotonated amino group of one GSH molecule to form Cd2(GSH)1, and the second GSH molecule quickly bounded to Cd2+ ions to form Cd2(GSH)2.This work studied the chelating reaction between metal ions and bioactive glutathione at single-molecule level without labeling and chemical modification, and would be important to further understand intracellular mechanisms of detoxification of heavy metals and greatly expand the research field of nanopore single-molecule technique.

ObjectiveTo evaluate the reliability and validity of the of Disability Assessment Schedule Ⅱ of World Health Organization(WHO-DASⅡ) applied in assessment of the function of disabled athletes.Methods56 disabled people,26 wheelchair basketball athletes and 30 patients,were sampled and completed WHO-DASⅡ questionnaire.The test and re-test had been administrated in 10 days.Barthel Index(BI) and Sports Classification Test had been implemented for the functioning assessment.ResultsThe test-retest reliability for WHO-DASⅡ in six dimensions were: 0.978,0.807,0.938,0.877,0.998,0.935,0.986 and all were in very significant level(P<0.01).There were negative correlation between WHO-DASⅡ scores and BI in total and in every dimension,the correlation coefficients were:-0.77,-0.17,-0.71,-0.82,-0.33,-0.73,-0.61.The correlation coefficients between WHO-DASⅡ total and six dimensional scores and the grade of sports classification were:-0.741,-0.378,-0.806,(-0.541),-0.293,-0.510,-0.677.ConclusionWHO-DASⅡ can be used in assessing the function of disabled athletes.

Brain Concussion ; complications ; Hearing ; Hearing Disorders ; prevention & control ; Humans ; Thioctic Acid ; therapeutic use

Objective To investigate the effects of transplantated tumor capillary permeability under microbubble enhanced diagnostic ultrasound exposure.Methods Fourty eight rats were randomly divided into four groups after Walker 256 carcinomas were subcutaneousely implanted,named the control group (A),microbubbles group (B),ultrasound group (C),microbubbles and ultrasound group (D).Using Evans blue(EB) as the indicator for tumor capillary permeability,the microbubbles were injected through the vein with diagnostic ultrasound frequency as 1.75 MHz,mechanical index as 1.4.The spillover of EB was estimated under confocal laser microscope,meanwhile the contents of EB in the tumor tissues were calculated according to the standard curve and spectrophotometry.Results EB spillover was observed around the capillaries in the group D,while EB spillover was only observable on capillary in group A,B and C.The EB content was also significantly higher than those in group A,B and C.Conclusions Exposure to both diagnostic ultrasound and microbubbles results in increased capillary permeability of rat tumor tissues,which might become a potential therapeutic method on clinical chemotherapy.

Objective To compare bolus infusion and replenishment using real low mechanical index contrast enhanced ultrasound in assessing the change of renal cortical perfusion.Methods Using dopamine (i.v.) at the dose of 0.5,2.0,5.0μg · kg- 1 · min- 1 to change renal blood perfusion of 20 rabbits,then during bolus or contant injection of SonoVue,at coded pulse inversion mode,real-time contrast ultrasound was performed,the latter method needed destroying microbubble at a high MI when amplitude reach a steady state,then recording the replenishment,peak intensity(A) and time to peak (PPT) were obtained through raw time-intensity curve,and slope rate of TIC(k) was acquired by curve fitting,standard effective renal plasma flow(ERPF) was measured through 4-aminohippuric acid clearancerate method,meanwhile correlations between ERPF and parameters were analyzed,as well as the paired samples t test for each parameter before and after dopamine administration.Results The ascending branchs of raw TIC of bolus infusion increased sharply and were approximately straight,then descended gradually,while that of replenishment looked like two straightlines with different slopes,then stayed horizontal Both the value of A of two methods were positively correlated with ERPF ( r b =0.85,r re =0.66),and were different at the same ERPF,meanwhile the value of TTP were negatively correlated with ERPF( r b =-0.92,r re =- 0.76),and there were no statistically difference between the two methods.k from Gamma fitting was far from correct,while k from exponential fitting was apparently correlated with ERPF ( r re =0.77 ).Conclusions Both bolus injection and constant injection-replenishment method can assess renal cortical blood perfusion,TIC parameters A and TTP represent regional blood volume fraction and microbubble velocity respectively.Bolus-infusion with real low mechanical index is more precise and available.Comparing with k,TTP is more appropriate to reflect perfusion velocity.

Purpose To explore the relationship between the mutations of epidermal growth factor receptor ( EGFR) and KRAS genes and clinicopathological characteristics in patients with non-small cell lung cancers (NSCLC). Methods Clinical samples from 431 NSCLC patients were obtained for EGFR and KRAS gene analysis. PCR based direct DNA sequencing was used to investigate mutations in exon 18-21 of EGFR gene and codon 12 and 13 of exon 2 of KRAS gene. Results The overall EGFR mutation rate of primary NSCLC was 53. 6% (231/431) in this study cohort and eight cases showed double EGFR mutations. Mutation rates in female and male were 65. 2% (122/187) and 46. 9% (98/209), respectively. The mutation rate was higher in patients with non-smokers and adeno-carcinoma and adenosquamous carcinoma subtypes than in their counterparts (P<0. 05), with the percentage of 57. 2% (124/216), 60. 3% (199/330), 42. 9% (6/14), respectively. In squamous cell carcinomas and other subtypes, EGFR mutation rates were 11. 6% (5/43) and 11. 1% (1/9), respectively. The EGFR mutation types included exon 18 point mutations (4. 0%, 9/227), exon 19 deletion mutations (4. 5%, 101/227), exon 20 insert or point mutations (9. 7%, 22/227) and exon 21 point mutations (41. 4%, 94/227). Activating mutations of KRAS gene were detected in 7. 8%(31/396) of NSCLC. Twenty-eight patients showed codon 12 mutations ( G>T, G>A, G>C) , and three patients had codon 13 mutations ( G>A, G>T) . Most of these mutations were G to T transversion (64. 5%, 20/31). Conclusion Polymerase chain reaction-direct sequencing is a reliable and effective method for the detection of the EGFR and KRAS gene mutation in NSCLC patients. The mutation rate of EGFR is higher in Chinese patients, especial-ly in non-smoking female patients with adenocarcinoma.

Objective To investigate the feasibility of transfecting gene into HepG2 by therapeutic ultrasound combined with microbubble,and to explore the optimal ultrasonic parameters for high transfection efficiency.Methods HepG2 cells were cross-interval planted in 24-well plates.EGFP plasmid DNA and microbubbles were added to the cultured HepG2 and three parameters of the therapeutic ultrasound were optimized.Firstly,set ultrasonic intensity gradient (group A,from A1 to A5),which were 0.4 W/cm,0.8 W/cm2,1.2 W/cm2,1.6 W/cm2 and 2.0 W/cm2 respectively.Secondly,set the duty cycle gradient group (group B,from B1 to B3),which were 10％,20％ and 50％ respectively.Lastly,set the exposure time group(group C,from C1 to C3),which were 30 s,90 s and 180 s.After 24 hours,the expression of GFP was observed by fluorescence microscopy,the transfection rates was detected by flow cytometry,the cell death were assessed by trypan blue exclusion.Results The plasmid transfection efficiency was varied under different ultrasonic parameters.Within a certain range,the increasing of parameters can improve the transfection efficiency,but when the parameters were too large (eg.the intensity＞1.6 W/cm2 or 50％ duty cycle),the actual transfection efficiency decreased due to the increased cell death.When the ultrasonic intensity was 1.2 W/cm2,the transfection efficiency and mortality were better than the other subgroups of group A.When the duty cycle was 20％,the transfection efficiency and mortality rate were better than the other subgroups of group B.Continue to increase the exposure time over 90 s was not statistically significant (P ＞0.05) for transfection efficiency and cell mortality.Conclusions The ultrasound-targeted microbubble destruction is an efficient method for gene delivery in vitro.The transfection efficiency vary greatly under different parameters,so optimization parameters is conducive to the promotion of gene transfection.

Objective To explore the effect of Fas and caspase-3 on apoptosis in the white matter damage(WMD) neonatal rats.Methods The pups(45 in each group) were perfused at 30 min,1 h,4 h,12 h,1 d,3 d,7 d,14 d,21 d of recovery from hypoxia-ischemia(HI).Immunohistochemical technique was applied to investigate the changes in the expression of Fas and caspase-3 in periventricular white matter tissues.Apoptotic cells were detected in these tissues by TUNEL.Results Apoptosis index(AI) in the experimental group increased significantly at 4 h and reached the peak at 3 d after HI.No expression of Fas was found in the control group.The expression of Fas in the experimental group appeared at 30 min after HI,increased at 1 h,reached the peak at 12 h and lasted till 3 d.Caspase-3 in the experiment group was up-regulated,peaked at 1 d,demonstrating significant differences at 1 h,4 h,12 h,1 d,3 d and 7 d compared with the control group(P

Objective To investigate the feasibility and plan quality of the image-guided volumetric modulated arc therapy (VMAT) based voluntary deep exhale breath-holding technique in the stereotactic ablative body radiotherapy (SABR) for liver tumors.Methods Fifteen patients with liver tumors were involved in this study.All patients were immobilized with voluntary deep exhale breath hold (vDEBH) combined with real-time position management (RPM) respiratory gating system.Treatment was planned using VMAT with 2 modified partial arc and re-planned using intensity modulated radiation therapy (IMRT) technique for comparison.Dosimetric parameters were calculated for plan quality assessment.Quality assurance studies included absolute dose and multiple planar dose verifications,total monitor units and delivery time analysis.Daily cone beam computed tomography imaging was used to verify the motions.Results There were no significant dosimetric differences between VMAT and conventional IMRT plans (P ＞0.05).Both techniques were able to minimize doses to organs at risk including normal liver,kidneys,spinal cord,and stomach.However,the average monitor units with VMAT were significantly lower 28.1％ than those with IMRT(t =3.064,P ＜0.05).The average beam-on time in VMAT plans was 31.6％ shorter than that in IMRT plans(t =2.278,P ＜ 0.05).Conclusions The utilization of VMAT in the treatment planning of SABR for liver tumors under breath control mode has better dosimetrics.In comparison to conventional IMRT plans,VMAT plans have higher efficiency and feasibility.

Based on target cycling amplification and 3 ,4 ,9 ,10-perylenetetracarboxylic dianhydride derivative functionalized singal probe, an ultrasensitive electrochemiluminescence ( ECL) sensor was designed for the detection of lead ions. The hairpin substrate DNA was immobilized on the electrode through molecular self-assembly. In the presence of Pb2+and DNAzyme, the substrate was cleaved with single strand DNA fragments left on the electrode surface. Meanwhile, the target and DNAzyme was released for another cleaving circularly. As a result, the single strand DNA fragments hybridized with the assist hairpin probe H1, which leaded to the fabrication of H2 labeled with the 3 , 4 , 9 , 10-perylenetetracarboxylic dianhydride derivative functionalized hollow gold nanoparticles. With the increasing concentration of Pb2+, much more signal probe was been captured and the ECL signal of the biosensor in peroxydisulfate ( S2 O2-8 ) solution would increase. An ECL assay demonstrates that the sensor has a good linear response to Pb2+ concentration in the range of 1í10-12 mol/L-1í10-6 mol/L, with a detection limit of 1í10-12 mol/L. The fabricated sensor shows good selectivity toward Pb2+against other common metal ions.